Summing shear capacities
Summing shear capacities
(OP)
2305.3.8 allows shear capacities to be added when applied to both faces of the wall. Does the limitation of 350 plf apply to each face separately? In other words, can I go up to 700 plf without requiring 3x members?






RE: Summing shear capacities
RE: Summing shear capacities
Thanks
RE: Summing shear capacities
In the IBC 2000, Table 2306.4.1, footnote h. indicates that "Where panels are applied on both faces of a wall and nail spacing is less than 6 inches o.c. on either side, panel joints shall be offset to fall on different framing members. Or framing shall be 3-inch nominal or thicker and nails on each side shall be staggered".
RE: Summing shear capacities
Yes (h) describes the option of 3x members or offset panels for wall applied to both faces and less than 6" nailing.
I am in a mostly "D" SDC so (i) also applies.
If I have a 240 plf on each face (not less than 6" nailing) the total allowable would be 480 plf. But (i) says that if I go over 350 plf (ASD) then I need 3x members and joint sill plate nailing staggered. Or does the 350 limit apply to each face separately.
Thanks
RE: Summing shear capacities
RE: Summing shear capacities
RE: Summing shear capacities
RE: Summing shear capacities
The increase to 3x allows less potential for sole plate splitting.
RE: Summing shear capacities
RE: Summing shear capacities
Sorry to beat this to a pulp, but (h) implies that you can use 6" OC nailing on each side and not use 3x. Also, I am typically referring to 2x6-framed walls. With the 1 3/8” (8d) fastener penetration on a 2x6 would seem to be potentially less damaging than a 2x4.
By the time you apply to both sides and possible stagger the panel edges it is probably easier and cheaper to just go to 3x members.
Thanks,
RE: Summing shear capacities
I agree that the code reads such that 2x members are acceptable given the staggered attachment on opposite sides. This clearly reflects a concern that the studs may split with the increased nailing patterns.
nonetheless 2x's are OK the way I read it.
My question is whether or not a dbl 2x stud will serve as an appropriate alternate to the 3x. Is there a particular condition that this idea does not account for? I agree that the an increase in the stud thickness improves shearwall rigidity.
BUT... In our area builders see 3x and ask, "what is that?"
Thanks